Lenticular overlays give images the appearance of depth or motion. A lenticular image is created using a transparent upper layer having narrow, parallel lenticules or semi-cylindrical lenses on an outer surface, and an image-containing substrate which projects images through the lenticules. The two layers form a lenticular system wherein different portions of an image are selectively visible as a function of the angle from which the system is viewed. If the image is a composite picture made by bringing together into a single image a number of different photographs of a scene photographed from different angles, and the lenticules are vertically oriented, each eye of a view will see different elements and the viewer will interpret the net results as depth of field. The viewer may also move his head with respect to the image thereby observing other views with each eye and enhancing the sense of depth. When the lenticules are oriented horizontally, each eye receives the same image. In this case, the multiple images give illusion of motion when the composite image is rotated about a line parallel to a line formed by the viewers eyes.
Whether the lenticules are oriented vertical or parallel, each of the viewed images are generated by lines of images which have been interlaced at the frequency of the lenticular or line blocking screen. Interlacing lines of each image is referred to as interdigitation. Interdigitation can be better understood by using an example four images used to form a composite with a material having three lenticules. In this example, line 1 from each of the four images is in registration with the first lenticule; line 2 from each of the four images is in registration with the second lenticule; etc. Each lenticule is associated with a plurality of image lines or an image line set, and the viewer sees only one image line of each set with each eye for each lenticule. It is imperative that the line image sets be registered accurately with respect to the lenticules, so that a proper picture is formed when the assembly is viewed.
Lenticular images 60, as shown in FIG. 1, are currently created by selecting several digital photographs, or digitizing photographic prints, and combining the individual photographs. In this example, a composite image comprised of eight photographs is scanned onto recording medium 62 by an eight-sided polygon 70. Facet 71 of polygon 70 lays down scanline 81 relating to a first original image. Facet 72 lays down scanline 82 from a second original image. This process is repeated with each facet laying down one line from each of the eight individual images until medium 60 has been advanced the width of one lenticule 64. The process is repeated with facet 71 laying down a second line from the first image as scanline 91, facet 72 laying down a second line of a second original image as scanline 92, and so forth for facets 73-78, until the media 62 has been advanced the width of another lenticule 64. Thus, each original image is laid down by only one facet of polygon 70.
Using this method, or other similar methods, the photographs have already been taken and individual photographs selected and digitized to prepare a lenticular image. One such system is shown in U.S. Pat. No. 5,995,132. This is a retrospective process and is highly sensitive to laying down each line of each image, interlaced, in exact registration with each lenticule. Consumers who choose to have a lenticular image prepared may not know until the lenticular image is actually produced whether the results will be satisfactory. Since the lenticular print will not be ready until a period of time after the event has taken place, if the final results are unsatisfactory, the opportunity to retake the lenticular image will have passed.
There is a need for a prospective process, which will be more consumer friendly, increase the use of lenticular images, and result in lenticular prints which capture the depth images or motion images that the photographer intended.